The Equator

The equator is the longest line of latitude on Earth. It runs about 40,075 kilometres, right around the planet’s widest point.

The Mitad del Mundo (“Middle of the World”) monument near Quito, Ecuador, marking the equator. Photo by Bbb, CC BY-SA 3.0, via Wikimedia Commons.

Countries the equator passes through, highlighted in red. Map derived from Equator_and_Prime_Meridian.svg, CC BY-SA 3.0, via Wikimedia Commons.

MCQ Questions

WORLDGEO0028

~40,075 km

The Equator, Earth’s longest parallel

Crossing three continents, three oceans, and thirteen countries.

Continents

South America, Africa, Asia

Oceans

Atlantic, Indian, Pacific

Countries on the Line

Including Ecuador, Kenya, Indonesia

Only Glacier

Volcán Cayambe

Ecuador, ~5,790 m, permanent snowcap

mcqquestion.comWorldGeo0028

📑 Contents

🌐 Definition and Countries

Where the Line Runs

Definition The equator is an imaginary line at 0° latitude, exactly midway between the North and South Poles. It divides Earth into the Northern and Southern Hemispheres.
Continents It crosses three continents: South America, Africa, and Asia.
Countries Thirteen countries sit directly on the equator, including Ecuador, Colombia, and Brazil in South America; Gabon, the Republic of the Congo, the Democratic Republic of the Congo, Uganda, Kenya, and Somalia in Africa; and Indonesia in Asia. It also skirts São Tomé and Príncipe.
Namesake Ecuador, the country, is named directly after the equator. The word “ecuador” is Spanish for “equator.”

🌊 Oceans, Water Bodies, and Climate

1. Physical Geography

Oceans The equator crosses three oceans: the Atlantic, the Indian, and the Pacific.
Lake Victoria It also passes directly through Lake Victoria, in East Africa. Not every major East African lake sits on the line, though. Lake Tanganyika, further south, lies entirely south of the equator.
Bulge Earth isn’t a perfect sphere. Its rotation makes it bulge slightly at the equator, so the planet’s diameter there is a little wider than pole-to-pole.

2. Climate

Day Length Countries on the equator generally have a tropical, equatorial climate. Day length stays close to 12 hours year-round, with little seasonal variation.
Rainfall These regions typically see high rainfall, often between 2,500 and 3,500 mm a year, and average daytime temperatures around 30°C.
Cayambe Volcán Cayambe, in Ecuador, is the only point on the equator with a permanent glacier. At nearly 5,790 metres, it stays cold enough to hold snow year-round, despite sitting on the tropical line.

Test Yourself

🚀 Marking the Line, and Using It

1. Monuments

Mitad del Mundo Several countries have built monuments marking where the equator crosses their territory. The best known is Mitad del Mundo, near Quito, Ecuador, built where a French expedition calculated the line in 1736.
GPS Correction Modern GPS measurements later found the true equator lies about 240 metres north of that monument. Ecuador built a second, more accurate marker nearby.
Kenya Kenya has a similar roadside marker near Nanyuki, a popular stop for travellers on the route north from Nairobi.

2. Why Rockets Launch From Here

Rotational Speed Earth spins fastest at the equator, at roughly 1,670 km/h, since a point there covers the planet’s full circumference once every 24 hours.
Launch Advantage A rocket launched eastward near the equator gets a free speed boost from that rotation, needing less fuel to reach orbital velocity.
Real Example The European Space Agency’s Guiana Space Centre, in French Guiana, sits close to the equator specifically to take advantage of this.